A method of obtaining image data for printing a circular pad having a radius R by forming ink blots having a radius r in an overlapping manner. The method can include: setting a base pitch as the base distance between adjacent ink blots, arranging the vector data of the pad in an x-y coordinate system, setting a first base point in the coordinate system, selecting a first determination point that is separated from the first base point by a unit distance along each of the x-axis and y-axis in any one direction of 45 degrees and 135 degrees, comparing the distance from the first base point to the first determination point with the base pitch, and storing the coordinates of the first determination point as print data if the distance from the first base point to the first determination point is greater than or equal to the base pitch.